This includes `gui_utils`, `init_draft_statusbar`, `init_tools`,
`messages`, `todo`, `translate`, `utils`.
These are added to the `draftutils` Doxygen group
so that the functions contained in each module are listed
appropriately in the automatically generated documentation.
The error is both sent to the log file and to the console
instead of only the log.
This is helpful to troubleshoot problems with the delayed
execution of commands, such as when testing a relatively
broken version like d7a9f2ebf9.
Small spacing fixes like imports in separate lines
for more clarity, and the position of the license.
Also use the new `messages` module to provide
the functions to print text to the console.
Use two `DEBUG` variables to print information about
the `ToDo` class in order to see the scheduled commands
when the graphical commands are executed.